xColor

xColor, a PHP graph script can be used to manipulate color values. It is powerful enough to be used in online graphics applications.

It can perform several types of operations with colors like:- Merging two colors with a given level the opacity- Invert a color- Complement two colors- Add two colors- Subtract two colors- Multiply two colors- Get the average between two colors- Lighten a color- Get parts of two colors- Get the grey version of a color- Get the Web safe version of a color- Get a color for text to contrast well on a given background color- Determine if a text color is readable on given background color- Get the distance between two colors- Get an array of gradient colors- Get the gradient level of a given color between colors